Focusing mechanism and device for telescopes

Abstract

A focusing system for an optical instrument such as a telescope comprises first and second tubes that extend in a longitudinal direction, the second tube shaped to define a bore such that the first tube extends into the bore; an optical element coupled to one of the first and second tubes for movement therewith; an elastically deformable element between the first tube and the bore defined by the second tube; and first and second rolling bearings supported at first and second longitudinally spaced apart sections of the elastically deformable element for rolling movement while supported at the first and second sections, the first and second rolling bearings in contact with the outer surface of the first tube, wherein relative movement between the first and second tubes in the longitudinal direction is facilitated by rolling movement of the rolling bearings along the outer surface of the first tube.

What is claimed is: 
     
         1 . A focusing system for an optical instrument such as a telescope, the focusing system comprising:
 a first tube that extends in a longitudinal direction;   a second tube that extends in the longitudinal direction, the second tube comprising a bore-defining surface shaped to define a bore that extends in the longitudinal direction wherein the first tube extends into the bore;   an optical element coupled to one of the first and second tubes for movement therewith;   an elastically deformable element located between an outer surface of the first tube and the bore-defining surface of the second tube and extending in the longitudinal direction; and   first and second rolling bearings supported at first and second longitudinally spaced apart sections of the elastically deformable element for rolling movement while supported at the first and second sections, the first and second rolling bearings in contact with the outer surface of the first tube;   wherein relative movement between the first and second tubes in the longitudinal direction is facilitated by rolling movement of the rolling bearings along the outer surface of the first tube.   
     
     
         2 . The focusing system of  claim 1  wherein the elastically deformable element is deformed from its non-stressed state such that restorative forces associated with the deformation of the elastically deformable element tend to force the rolling bearings into contact with the outer surface of the first tube. 
     
     
         3 . The focusing system of  claim 1  wherein the elastically deformable element is deformable such that the first and second longitudinally spaced sections of the elastically deformable element are displaceable in directions having directional components orthogonal to the longitudinal direction (e.g. having components in radial directions of the second tube). 
     
     
         4 . The focusing system of  claim 3  wherein the elastically deformable element is deformed such that the first longitudinal section of the elastically deformable element has a first displacement in a first direction having at least a component orthogonal to the longitudinal direction relative to a non-deformed state of the elastically deformable element and the second longitudinal section of the elastically deformable element has a second displacement in a second direction having at least a component orthogonal to the longitudinal direction relative to the non-deformed state of the elastically deformable element. 
     
     
         5 . The focusing system of  claim 4  wherein a magnitude of the first displacement is different from a magnitude of the second displacement. 
     
     
         6 . The focusing system of  claim 4  wherein a magnitude of the first displacement is the same as a magnitude of the second displacement. 
     
     
         7 . The focusing system of  claim 1  comprising one or more shafts, the one or more shafts extending between, and connected to, the elastically deformable element and the second tube to couple the elastically deformable element to the second tube. 
     
     
         8 . The focusing system of  claim 7  wherein the elastically deformable element is shaped to define one or more holes at locations between the first and second sections, the one or more shafts extending through corresponding ones of the one or more holes in directions having directional components orthogonal to the longitudinal direction. 
     
     
         9 . The focusing system of  claim 8  wherein the one or more shafts extend through one or more corresponding holes defined through the second tube. 
     
     
         10 . The focusing system of  claim 9  wherein at least one of the one or more shafts is threadably connected to at least one of: the elastically deformable element as the at least one of the one or more shafts extends through the corresponding one of the one or more holes defined in the elastically deformable element; and the second tube as the at least one of the one or more shafts extends through the corresponding one of the one or more holes defined through the second tube. 
     
     
         11 . The focusing system of  claim 9  comprising a support component, the support component located between the outer surface of the first tube and the elastically deformable element and wherein the one or more shafts extend through one or more corresponding holes defined through the support component. 
     
     
         12 . The focusing system of  claim 11  wherein at least one of the one or more shafts is threadably connected to the support component as the at least one of the one or more shafts extends through the corresponding one of the one or more holes defined through the second tube. 
     
     
         13 . The focusing system of  claim 7  wherein at least one of the one or more shafts is adjustable to alter a distance between the elastically deformable element and the second tube and wherein varying the distance between the elastically deformable element and the second tube varies an amount of deformation of the elastically deformable element. 
     
     
         14 . The focusing system of  claim 1  comprising a shaft that extends between and is connected to the elastically deformable element and the second tube and wherein the extension is in a direction having a directional component orthogonal to the longitudinal direction. 
     
     
         15 . The focusing system of  claim 14  wherein a position of the shaft relative to the second tube is adjustable and variation of the position of the shaft relative to the second tube varies an amount of deformation of the elastically deformable member. 
     
     
         16 . The focusing system of  claim 15  wherein the position of the shaft is threadably adjustable relative to the second tube. 
     
     
         17 . The focusing system of  claim 1  comprising first and second bearing supports located at the first and second sections of the elastically deformable element and wherein the first and second bearing supports are shaped to constrain the rolling movement of the first and second rolling bearings along the outer surface of the first tube to the longitudinal direction. 
     
     
         18 . The focusing system of  claim 1  wherein the first and second rolling bearings are substantially aligned with one another in the longitudinal direction. 
     
     
         19 . The focusing system of  claim 1  wherein the first and second rolling bearings comprising ball bearings or ball bearing assemblies. 
     
     
         20 . The focusing system of  claim 1  wherein the bore-defining surface of the second tube is shaped to define a first support and a second support, the first and second supports extending in the longitudinal direction and having contact surfaces in contact with the outer surface of the first tube, the contact surfaces having shapes complementary to a shape of the outer surface of the first tube.